The efficient, green, facile, mild and straightforward conversion procedure for the oxidation of cyclic ketones to lactones at room temperature utilizing potassium peroxydisulfate （K2S2O8） in acidic media is satisfa...The efficient, green, facile, mild and straightforward conversion procedure for the oxidation of cyclic ketones to lactones at room temperature utilizing potassium peroxydisulfate （K2S2O8） in acidic media is satisfactory to high yields without using traditional chlorinated solvents is reported. This oxidative reagent is cheap and friendly environmental procedure for industrial purposes than use of organic peracids.展开更多
As an excellent chemical fertilizer,Potassium Sulphate(K2SO4)could provide both potassium and sulfur elements for crops.However,it is well known that potassium resource is very poor in China.To understand the Crystall...As an excellent chemical fertilizer,Potassium Sulphate(K2SO4)could provide both potassium and sulfur elements for crops.However,it is well known that potassium resource is very poor in China.To understand the Crystallization Kinetics(CK)of K2SO4could be conducive to utilize the limited potassium resource,promote the yield and purity of K2SO4.In this study saturated solution of potassium sulphate was prepared according to the phase diagram of Mg2+、展开更多
40K is one of the most important atomic species for ultra-cold atomic physics. Due to the extremely low con- centration （0.012%） of 40K in natural abundance of potassium, most experiments use 4-10% enriched potassiu...40K is one of the most important atomic species for ultra-cold atomic physics. Due to the extremely low con- centration （0.012%） of 40K in natural abundance of potassium, most experiments use 4-10% enriched potassium source, which have greatly suffered from the extremely low annual production and significant price hikes in recent years. Using naturally abundant potassium source, we capture 5.4 × 10 6 cold 40K atoms with the help of a high performance of two-dimensional magneto-optical trap （2D＋ MOT）, which is almost three orders of magnitude greater than previous results without the 2D＋ MOT. The number of the 40K atoms is sufficient for most ultra-cold 40K experiments, and our approach provides an ideal alternative for the field.展开更多
A new stearic acid method(SAM) has been used to prepare ultrafine K2La2Ti3O10 nanocrystalline. Each state of synthesis process was followed by the use of FT IR analysis. The resulting materials have been characterized...A new stearic acid method(SAM) has been used to prepare ultrafine K2La2Ti3O10 nanocrystalline. Each state of synthesis process was followed by the use of FT IR analysis. The resulting materials have been characterized by means of XRD, TEM, BET surface area analysis. The acid exchanging property of the obtained product was also studied. The experimental results showed that comparing with the product of traditional solid state reaction, the particle size of the K2La2Ti3O10 synthesized by SAM is greatly reduced, BET surface area is high(more than 11.83m2· g- 1) and has different acid exchanging properties. It can be easily exfoliated in 2mol· L- 1 HNO3 solution.展开更多
The carbonation characteristics of K2CO3/Al2O3 supported sorbent for CO2 capture was investigated with thermogravimetric apparatus(TGA),X-ray diffraction(XRD),scanning electron microscopy analysis(SEM)and N2 adsorptio...The carbonation characteristics of K2CO3/Al2O3 supported sorbent for CO2 capture was investigated with thermogravimetric apparatus(TGA),X-ray diffraction(XRD),scanning electron microscopy analysis(SEM)and N2 adsorption.The results showed that the carbonation rate of K2CO3 before being loaded on Al2O3 was slow.However,the K2CO3/Al2O3supported sorbent showed excellent carbonation performance.The difference in carbonation behavior between K2CO3and K2CO3/Al2O3supported sorbent was analyzed from the microscopic view.The analytical reagent K2CO3 sample was of monoclinic crystal structure and could react quickly with H2O in the experimental carbonation environment to produce K2CO3·1.5H2O,which was unfavorable to carbonation reaction.When K2CO3was loaded on Al2O3,the surface area and porosity of the sorbent was improved greatly.So the carbonation properties of the K2CO3/Al2O3 supported sorbent was also improved.展开更多
基金support and purchase of Hewlett-Packard 6890 GC-Hewlett-Packard 5973N MSD instrument.
文摘The efficient, green, facile, mild and straightforward conversion procedure for the oxidation of cyclic ketones to lactones at room temperature utilizing potassium peroxydisulfate （K2S2O8） in acidic media is satisfactory to high yields without using traditional chlorinated solvents is reported. This oxidative reagent is cheap and friendly environmental procedure for industrial purposes than use of organic peracids.
基金financial support of National Nature Science Foundation (21376178)TIDA giant growth plan (2011-XJR13020)+3 种基金Tianjin Science and technology support program (12ZCDZSF06900)Tianjin University of Science and Technology fund for scientific research (20120119)Tianjin education commission program (20130509)Research fund for the doctoral program of higher education of China(20131208120001)
文摘As an excellent chemical fertilizer,Potassium Sulphate(K2SO4)could provide both potassium and sulfur elements for crops.However,it is well known that potassium resource is very poor in China.To understand the Crystallization Kinetics(CK)of K2SO4could be conducive to utilize the limited potassium resource,promote the yield and purity of K2SO4.In this study saturated solution of potassium sulphate was prepared according to the phase diagram of Mg2+、
基金Supported by the National Key Research and Development Program of China under Grant Nos 2016YFA0300600 and2016YFA0301500the National Natural Science Foundation of China under Grant Nos 11474347,61227902 and 61775232
文摘40K is one of the most important atomic species for ultra-cold atomic physics. Due to the extremely low con- centration （0.012%） of 40K in natural abundance of potassium, most experiments use 4-10% enriched potassium source, which have greatly suffered from the extremely low annual production and significant price hikes in recent years. Using naturally abundant potassium source, we capture 5.4 × 10 6 cold 40K atoms with the help of a high performance of two-dimensional magneto-optical trap （2D＋ MOT）, which is almost three orders of magnitude greater than previous results without the 2D＋ MOT. The number of the 40K atoms is sufficient for most ultra-cold 40K experiments, and our approach provides an ideal alternative for the field.
文摘A new stearic acid method(SAM) has been used to prepare ultrafine K2La2Ti3O10 nanocrystalline. Each state of synthesis process was followed by the use of FT IR analysis. The resulting materials have been characterized by means of XRD, TEM, BET surface area analysis. The acid exchanging property of the obtained product was also studied. The experimental results showed that comparing with the product of traditional solid state reaction, the particle size of the K2La2Ti3O10 synthesized by SAM is greatly reduced, BET surface area is high(more than 11.83m2· g- 1) and has different acid exchanging properties. It can be easily exfoliated in 2mol· L- 1 HNO3 solution.
文摘The carbonation characteristics of K2CO3/Al2O3 supported sorbent for CO2 capture was investigated with thermogravimetric apparatus(TGA),X-ray diffraction(XRD),scanning electron microscopy analysis(SEM)and N2 adsorption.The results showed that the carbonation rate of K2CO3 before being loaded on Al2O3 was slow.However,the K2CO3/Al2O3supported sorbent showed excellent carbonation performance.The difference in carbonation behavior between K2CO3and K2CO3/Al2O3supported sorbent was analyzed from the microscopic view.The analytical reagent K2CO3 sample was of monoclinic crystal structure and could react quickly with H2O in the experimental carbonation environment to produce K2CO3·1.5H2O,which was unfavorable to carbonation reaction.When K2CO3was loaded on Al2O3,the surface area and porosity of the sorbent was improved greatly.So the carbonation properties of the K2CO3/Al2O3 supported sorbent was also improved.
